Question

if there are two groups with 75 and 65 as harmonic mean and containing 15 and 13 observations then the combined HM is given by​

Answer 1

Answer:

70

Step-by-step explanation:

Given  

if there are two groups with 75 and 65 as harmonic mean and containing 15 and 13 observations then the combined HM is given by

Now the reciprocal of the given terms are 1/75 and 1/65 respectively.

Now the sum of the reciprocals in first group will be 1/75 x 15 = 1/5

Also second group will be 1/65 x 13 = 1/5

Now sum of reciprocals of all 28 observations will be 1/5 + 1/5 = 2/5

So mean will be 2/5 / 28 = 1/70

So harmonic mean of all the numbers together will be 70

Answer 2

Answer:

Step-by-step explanation:

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